Thanks for the pointer. The paper there is very interesting. I'm
glad I regularly use Tor and NoScript.

Regards

-Mark

You can have a look at https://panopticlick.eff.org/ for instance to
see how information exposed by your browser makes you traceable.
Every new "user-agent"-like feature will give more and more bits of
uniqueness, at a certain point the aggregation of all this information
would effectively allow to create a permanent serial number tied to an
user or handful of users.